Emergency flotation devices are required on many aircraft to provide emergency assistance to passengers in the event the aircraft experiences an emergency situation and is forced down in water. Emergency flotation devices generally include systems designed to float the aircraft, systems for emergency life rafts and life vests for individual occupants.
One example of an airplane flotation system is shown in U.S. Pat. No. 1,776,865. The system includes inflatable bags located in a forward portion of an airplane and is manually operated by a pilot. The bags are folded and stored in a non-inflated state within closed compartments that are dedicated to storage of the bags. The system utilizes pressure cylinders to sequentially unlock doors of the compartments and inflate the inflatable bags. During operation the pilot activates the pressure cylinder by releasing pressurized gas. After inflation, the pilot is required to pull a cord that places the pressure cylinder into an intermediate position to block further fluid flow between the pressurized fluid. A first disadvantage of the system is that it requires the bags to be folded and stowed directly in the compartments. As a result, inspection of the system would require removal of the bags from the compartment and re-stowing or replacement of the bags would require significant time so that the bags could be folded and stowed. Another disadvantage is that the pressure cylinders are located within the airplane fuselage such that they are not readily accessible. As a result, inspection, repair and/or replacement of those components is difficult. A still further disadvantage is that it requires manual operation by the pilot even after the initial activation of the system.
U.S. Pat. No. 2,264,321 to Manson, describes a life-saving device that includes an inflatable life raft that is stowed directly in a compartment dedicated to the life raft on the side of a vehicle such as an airplane. The compartment is closed by a pair of hinged doors that are spring-loaded to urge them into an opened position. The doors are held closed by pins that extend through meshing lugs that are included on the doors. A pull cord is secured to the pins and a valve on an inflating-gas container so that pulling on the cord sequentially removes the pins from the lugs and operates the valve to permit the flow of gas from the container to the raft. The cord fully disengages from the gas container after the valve is operated. A first disadvantage of the system is that it requires the life raft to be folded and stowed directly into a dedicated compartment. As a result, inspection and/or replacement of the life raft may be difficult. Another disadvantage of the system is that the pins may be disengaged without a complete activation of the system. In addition, the pull cord may become bound which may result in the pin disengaging without activation of the gas container. A further disadvantage is that the gas container valve does not include a mechanism to close the gas path between the gas container and the raft after the raft is inflated.
An additional disadvantage of the systems described above is that in order to retrofit an aircraft with such a system a compartment, such as a baggage compartment, would have to be converted and dedicated to the floatation system. As a result, storage space would be significantly reduced.
In view of the above, there exists a need for an emergency floatation system that may be mounted to a portion of the plane that is easily accessible. There is also a need for a system that can be installed during original manufacture of the aircraft, or as an aftermarket improvement. It is important that the system provide little or no impairment of the standard equipment and components of the aircraft.